Hi IDG397, Tanking major exception to your Post concerning color case hardening of the Model 70 receiver on two counts. First, certainly not taking "purist" term, to my mind, in the execution of a Model 70 "restoration" as absolutely "Not" in any sense of the term. Second the balance of what appears suggested as innocuous aesthetics as factually of great significance in tradeoff!
Contrast: Lever mild carbon steel "color case hardening" of era 'best in class' action designs strength factors and metallurgy available. Of "chamberings" also in reflection of pressures/stresses contemplated... All those factors, add "pursuant to manufacturer oversight"! What the Winchester-competent factory renders, let no man put asunder! Net of color case hardening "quality restoration... Fine!
As moved to Bolt action rifles, contemplating inherently greater chamber strengths, adding two 'tech generations'; later with "Nickel Steel" improvement" in route to "Chrome Moly". Execution in Model 70 Receiver, bolt and barrel steel. A steel which may itself reflect some scientifically determined & controlled "surface hardening" of an era decades past in use upon materials similarly of decades past as "best available"... The 'balanced purview' of worthiness. Even in such 'tech', color case hardening featuring infusion of carbon in some high wear applications (such as gear teeth) possible and appropriate of continuous effects of wear. But not necessarily where occasional high stress "component impact deformation" such as bolt lugs to receiver mating surfaces, a different 'spec' proposition! The metallurgy "tailored for the metal in respect of "application"!
Undoing factory specs themselves based on hard core materials science... For the sake of "pretty"... What the heck? The term "restoration" reaching "silly'. Moreover misrepresentation as unnecessary hazard of deviating from most worthy of 'pricey' CroMo utilization!
The 'net-net', of what's good, acceptable, factual "restoration" in a Model 9x lever rifle - IF properly accomplished - entirely "your rifle, your choice". But requesting kindly don't speak of "restoration" as backyard smithy "rule of thumb science" in metallurgy!
Whew...! And just wordy take!
Best and no offense intended... Just advocacy!
John